The present invention relates to automotive vehicles, and in particular to a control system for towed automotive vehicles, such as trailers and semi-trailers, and a method of operating control systems for vehicles with trailers.
Trailers play an important role in the transportation of goods. In addition to the great variety of trailers used in Class 7 and 8 heavy truck transports, there are many trailers of a smaller nature, such as those towing boats, household goods, harvested crops, automobiles, and so on. The proper control of trailers is necessary for their safe and economical operation, both on and off the highway. This is especially important with the higher speeds now allowed on interstate and non-interstate highways. What is needed is a trailer control system that will allow vehicle operators to automatically remain in control of their vehicle prime mover and trailer during difficult driving situations. These situations may include those in which the driver may understeer or oversteer the trailer, or situations in which the trailer may experiences a yaw rate greater than the driver can control, or a roll-over force greater than the driver can control.
In one embodiment of the present invention, a control system is provided for a combination vehicle having a trailer, said control system comprising a computer, a memory accessible to the computer, sensory inputs to the computer and output signals from the computer. There are also at least two brake controllers for wheels on the trailer, said controllers in communication with the computer, wherein the computer receives sensory inputs and calculates brake controller movements to control the movement of the trailer.
The invention may be further embodied in a method of controlling braking of a combination vehicle. The method comprises measuring a plurality of parameters relating to movements and speed of a prime mover and a trailer of the combination vehicle. The method then calculates at least one steering error selected from the group of a braking error, a yaw steering error, and a trailer roll. The method then calculates making a correction to the speed of at least one wheel on the trailer to correct the steering error. Then the method applies the correction by applying a braking force to the at least one wheel. Many other embodiments of the invention are possible.